Folding box forming machine



Aug. 29, 1961 5. J. HOYRUP FOLDING BOX FORMING MACHINE 5 Sheets-Sheet 1 Filed March 6, 1959 A n 0 T w M my w 0 T m H A 5 w I n d. m J av. r 3 y 5 Aug. 29, 1961 5. J. HOYRUP 2,997,923

FOLDING BOX FORMING MACHINE 5 Sheets-Sheet 2 Filed March 6, 1959 INVENTOR. Sigurd Johannes Hoyrup A TTORNEY Aug. 29, 1961 5. J. HOYRUP FOLDING BOX FORMING momma:

5 Sheets-Sheet 3 Filed March 6, 1959 YNVENTOR. Sigurd Johannes Hoyrup Y. E N M T T A Aug. 29, 1961 5. J. HOYRUP FOLDING BOX FORMING MACHINE 5 Sheets-Sheet 4 Filed March 6, 1959 mmvroa. S/gu/ d Johannes Hqyrup BY M We (,1, A TTORNEY Aug. 29, 1961 s. J. HOYRUP FOLDING BOX FORMING MACHINE Filed March 6, 1959 Fig. 5

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5 Sheets-Sheet 5 IN VHV TOR.

Sigurd Jobanne; Hoyrup (.4; ATTORNEY United States Patent 2,997,928 FOLDING BOX FORMING MACHINE Sigurd Johannes Hoyrup, Monta Vista, Calif., assignor to Baljak Corporation, Wilmington, Del., 21 corporation of Delaware Filed Mar. 6, 1959, Ser. No. 797,676 18 Claims. (CI. 93-51) This invention relates to improvements in box assembly machines of the plunger and die type in which a flat blank of foldable sheet material is converted into box form by forcing the blank into a folding die in which the blank assumes box form about the plunger.

The invention has particular application to machines for assembling glued boxes. In these machines the glued box portions are subjected to compressive force in a compression die having opposite pressure elements or plates which exert compressive force on the box while the box is being supported internally by the plunger.

During the application of compressive force the plunger must be at rest while other portions of the box machine should preferably continue in motion. The

requirement of arresting the plunger complicates the drive mechanism and poses operational problems, par- 'ticularly in fast running machines having a high production rate.

The invention provides an improved machine in which the reciprocating drive mechanism which actuates the plunger may operate continuously and uninterruptedly while the plunger proper is decelerated, arrested, and finally accelerated to catch up with the drive mechanism which in the meantime has advanced, then moved at substantially the same rate as the drive mechanism, and is again decelerated and arrested during the next cycle of operation.

This is accomplished by a pressure fluid coupling or motion transmitting means which is interposed between the uninterruptedly operating drive mechanism and the plunger. 7

The invention provides a smoothly operating machine which is free from pounding, vibration and noise, comprising elements of relatively small mass which are alternately accelerated and retarded. These elements of small mass are divorced from the relatively heavy mass of the continuously operating drive mechanism. Deceleration, stopping and acceleration are smooth by reason of the pressure fluid action, the operation of the machine is rapid and its output is high. The pressure fluid elements which connect the plunger with the drive permit the plunger to move at certain times at higher linear speeds than the drive, and at other times at lower linear speeds while the main drive, more particularly, the reciprocating member, the gears, cranks, levers or other elements which connect it with the prime mover, for example an electric motor, operate at constant speed.

The various objects, features and advantages of this invention will appear more fully from the detailed description which follows accompanied by drawings showing, for the purpose of illustration, a preferred embodiment of the invention. The invention also resides in certain new and original features of construction and a combination of elements hereinafter set forth and claimed.

Although the characteristic features of this invention which are believed to be novel will be particularly pointed out in the claims appended hereto, the invention itself, its objects and advantages, and the manner in which it may be carried out may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of it, in which:

FIG. 1 is a diagrammatic drawing illustrating certain 2,997,928 Patented Aug. 29, 1961 2 portions of the plunger and die mechanism and portions of the drive;

FIG. 2 is a perspective view of the plunger and die;

FIG. 3 is a perspective view of the pressure fluid mechanism in a preferred form;

FIG. 4 is a perspective view of the pressure fluid mechanism during a certain phase of its operation;

FIG. 5 is a sectional view of a flow control element used in the mechanism of FIGS. 3 and 4; and

FIG. 6 is an elevational view, partly in section, of a hydraulic snubber for the plunger.

In the following description and in the claims various details will be identified by specific names for convenience. The names, however, are intended to be generic in their application. Corresponding reference characters refer to corresponding parts in the several figures of the drawings.

The drawings accompanying, and forming part of, this specification disclose certain specific details of construction'of the invention for the purpose of explanation of broader aspects, but it is understood that constructional details may be modified in various respects without departure from the principles of the invention and that the invention may be incorporated in other structural form than shown.

FIG. 1 shows a box blank 11 having a main panel M, end panels B, side panels S and glue flaps F underneath a plunger 12 and above a die 13. The die is a combined folding and compression die and comprises front and rear blank folding elements 14 and 15 adapted to engage the side panels S and fold the side panels against the sides 18 and 19 of the plunger 12.

Further blank folding elements 16 and 17 are adapted to engage the end panels E to fold these against the end surfaces 20 and 21 of the plunger 12. Glue applicators 22 and 23 are provided at the four corners of, and slightly above, the die 14. The two glue applicators nearest the observer are omitted for the sake of clarity.

The glue applicators prefold the flaps F at an angle to the side panels S and apply adhesive to the outside of the flaps so that upon entry of the blank into the die the flaps F overlie the end surfaces 20 and 21 of the plunger and the end panels E lie thereover and become adhesively secured thereto.

A pair of pressure plates 24 and 25 are linked to power levers 26 and 27 at 28 and 29. One end of the levers is pivotally supported at 30 and 31 and a hydraulic servo-motor 32 is pivotally connected to the opposite end of the power levers at 33 and 34. The piston 35 of the servo-motor subdivides the servo-motor cylinder 36 into a left chamber 37 and a right chamber 38. Pressure lines 39 and 40 lead to the chambers of the servo-motor. Fluid under pressure entering the left chamber 37 through the line 39 causes the power levers 26 and 27 to be drawn together and the plates 24 and 25 to exert compressive force on a folded box moved into the die by the plunger 12.

FIG. 1 also shows in simplified form the major elements of the drive mechanism comprising an electric motor 41 having a pulley 42 which drives a gear 43 on a pinion shaft 44 through a chain 45. A pinion 46 on shaft 44 meshes with a gear 47 on a crank shaft 48 carrying a crank 49. The crank is linked to an oscillating arm 50 by a connecting rod 51. The oscillating lever oscillates about a fixed pivot 52 and the free end of the arm 50 is linked to a reciprocating cross head 53 by a further connecting rod 54. The cross head is slidably supported on a column 55 and supports one end of a drive bar 56 whose other end is supported in a similar cross head 57 on the opposite side of the machine. The drive bar supports the plunger 12 in a manner later to be described.

The motor is supplied with power from a source 58 and controlled by switches 59 and 60. The first switch 59 is operated by a cam 61 on the crank shaft 48. The shape of the cam is such that the switch 59 opens whenever the drive bar 56 approaches the lower end of the down stroke at which moment the plunger 12 enters the die 13. This would stop the machinewere it not for the presence of a second switch 60 which then closes and maintains the circuit unbroken. The second switch, as will later be seen, is operated by a cam 62 moving with the plunger 12. The purpose of this arrangement is to stop the machine if for any reason the plunger is prevented from entering the die.

The foregoing description covers the essential elements of the driving mechanism in a simplified combination of assembly. In actual practice the mechanism is somewhat more complex and refined and comprises, for example, means for varying the speed of the drive, relay control mechanisms in the electric circuit, and other details not essential to an understanding of the present invention. These details are disclosed in the copending application of Edward J. Pagendarm, Serial No. 797,688, filed March 6, 1959, (docket No. 5911).

The plunger drive bar 56 (FIG. 3) carries two brackets 63 and 64 on which a common base plate 65 is mounted. The base plate 65 carries two vertical cylinders 66 and 67, each containing a piston 68 and 69 whose piston rods 70 and 71 extend through the top of the cylinders and are connected by a piston plate 72.

The top ends of the cylinders 66 and 67 are held in place by a top plate 73 which is rigidly connected to the base plate 65 by spacer rods 74. Two slide bearing sleeves 75 and 76 are also held between the base plate 65 and the top plate 73. Plunger rods 77 and 78 extend slidahly through the sleeves 75 and 76 and carry a plunger plate 79 at their lower ends. The plunger 12 is secured to the plunger plate 79 by a bolt 80.

The pistons 68 and 69 divide the cylinders into upper chambers and lower chambers, the upper chambers being in communication with the atmospheric air through air filters 81 which keep out'dust. The lower chambers are in communication with the atmosphere through similar filters 81. Valve assemblies 82 and 83 are interposed between the lower chambers and the atmosphere, the assembly 83 being mounted upside down with respect to the valve assembly 82.

The valve assemblies are shown in detail in FIG. 5. Each valve assembly comprises basically a housing 84 tapped at both ends for threaded connection with appropriate fittings. Intermediate its ends the housing is divided by an internal cross wall 85. The internal wall has two apertures 86 and 87 through which one end portion of the housing may communicate with the other. The aperture 86 is variable in size by a needle valve 88, the other aperture 87 is controlled by a check valve 89. The needle valve 88 permits restricted passage of air through the valve assembly in the direction of the axis of the valve housing. The check valve 89 permits relatively free flow of air in one direction, but seals its passage when the air flows in the opposite direction.

As a result of the inverted mounting of valve assembly 83 with respect to the assembly 82, atmospheric air enters freely into the lower chamber of the cylinder 67 when its piston 69 moves upwardly, whereas downward motion of the same piston meets with resistance because air being forced out of the lower chamber causes the check valve 89 to close and can escape only through the restricted needle valve 88. Thus downward motion of the piston within the right cylinder 67 is restrained whereas upward motion is unrestrained.

The reverse applies with respect to the piston 68 within the left cylinder 66. Upward piston motion, causing air to enter its lower chamber, is restrained because air can only enter through its needle valve 88 while its check valve 89 is closed. Downward motion, however, caus- 4 ing air to escape from the lower chamber is unrestrained because the air escapes freely through the check valve 89.

An adjustment of the needle valve 88 permits any desired degree of restraint to be imposed on the upward motion and the downward motion of the pistons with respect to the cylinders and thus upon the plunger 12 with respect to its drive bar 56. The restraint is of an elastic nature due to the compressibility and the expansibility of air.

In order to prevent the pistons from bottoming in the respective cylinders 66 and 67, a pair of buffers 90 are mounted on the top plate 73 on which steps 91 on piston plate 72 may seat.

It was previously mentioned that the downward mo tion of the plunger 12 is arrested in the position in which compressive force is exerted on the folding box.

In order to prevent sudden stops of the plunger from producing a corresponding impact on the drive, a hydraulic snubber mechanism is provided comprising a snubber. 92 mounted on the framework on the machine and a striker pad 93 on the piston plate 72.

The snubber comprises a cylinder 94 containing a piston 95 having a narrow groove or passage 96 through which fluid may pass from a lower chamber 97 of the body 98 into an upper chamber 99. The upper chamber 99 is in communication with a reservoir 100 through a line 101. The piston 95 is under the action of a spring 102 tending to maintain the piston 95 raised. When the piston is depressed it offers increasing resistance to displacement due to the fact that the flow resistance of the passage 96 between the upper chamber 99 and the lower chamber 97 increases. The increasing resistance offered by the snubber arrests the plunger gently.

When the plunger reaches its lowest position and is arrested, the pressure plates 24 and 25 are urged to gether. As a result the plunger is temporarily clamped between the plates and rendered immovable while compressive force is being exerted on the glued ends of the box carried by'the plunger.

The drive bar 56 of the plunger may start its upward stroke without delay while the plunger proper stays in place until the compressive forceof the plates 24 and 25 is released. During the upward motion of the bar 56 the cylinders 66 and 67 move in an upward direction with respect to their pistons which are at rest by reason of being attached to the plunger. During this motion air is compressed in the lower chamber of the cylinder 67 and escapes only slowly because of the restriction of air flow by the needle valve 88 of the assembly 83. This compressed air represents a resilient driving force which drives the plunger 12 upwardly as soon as the compressive force exerted by the pressure plates 24 and 25 is released. This action is gentle and continues until the pistons are raised so far that the stops 91 seat on the buffers 90, whereafter the upstroke of the plunger 12 continues at the same rate as the upward motion of the drive bar 56.

When the drive bar 56 comes to rest in its upper return position, the plunger 12 is permitted to continue traveling in an upward direction for a certain distance, thereby separating the stops 91 from the buifers 90 while the drive bar 56 moves downwardly. The plunger 12 comes to rest in a top position and its motion is then reversed by the creation of a vacuum in the left cylinder 66 into which air can enter only slowly because of the restriction to air flow imposed by its needle valve 86.

The plunger then moves through its downward stroke forcing the next blank into the die. The next blank ejects thelast formed box whose side walls are bowed in slightly by central resilient projections of which one is visible at 103.

The plunger comes to rest when its striker pad 93 is arrested by the snubber head 104.

During the lower portion of the downstroke the plunger cam 62 actuates the switch 60 which closes and maintains the drive circuit unbroken during the phase of the operation during which the switch 5 9 opens.

If the downstroke of the plunger\12 is obstructed, for example by accidental feeding of several cohering blanks or some other obstacle in the path of the plunger, the pneumatic mechanism permits the drive bar 56 to continue moving until the entire drive mechanism is stopped immediately thereafter due to failure of the plunger switch 60 to close.

Obviously structural details of the yielding drive mechanism may be modified in various respects to fit the requirements of individual installations.

What is claimed is:

1. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; and a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air.

2. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; and a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in' said cylinder and subdividing said cylinder into two chambers, and air passage means providing communication between at least one of said chambers and the surrounding atmospheric air, said air passage means including means for restrictingflow of air into said chamber in a different degree than flow of air from said chamber.

3. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; and a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and air passage means providing communication between at least one of said chambers and the surrounding atmospheric air, said air passage means including means for restricting the flow of air through said passage, and a check valve in parallel with said restricting means.

4. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; and a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder, means providing a passage for air between the cylinder and the surrounding atmospheric air, first air passage restricting means for restricting the flow of air between cylinder space and the surrounding atmospheric air during movement of the plunger relatively to the drive means in one direction, and second passage restricting means for restricting flow of air during movement of the plunger relatively to the drive means in the opposite direction.

5. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; and a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder, air passage means between the cylinder and the surrounding atmospheric air, first passage restricting means for restricting the flow of air between cylinder space and the surrounding atmospheric air during movement of the plunger relatively to said drive means in one direction, a first check valve parallel to said first passage restricting means, said check valve being oriented to close to passage of air during movement of the plunger relatively to the drive means in one direction, but open to passage of air during movement of the plunger relatively to the drive means in the opposite direction, second passage restricting means for restricting the flow of air between cylinder space and the surrounding atmospheric air during movement of the plunger relatively to said drive means in the opposite direction, and a second check valve parallel to said second Passage restricting means, said second check valve being oriented to close to passage of air during movement of the plunger relatively to the drive means in the opposite direction, but open to passage of air during movement of the plunger relatively to said drive means in said one direction.

6. A box forming machine as set forth in claim 5 in which said two passage restricting means are individual ly adjustable.

7. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a pneumatic coupling between said plunger and said drive means, the coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air; and means for resetting the plunger relatively to the drive means at least once during each cycle of the drive means, a cycle comprising one back and forth motion of said drive means.

8. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a pneumatic coupling between said plunger and said drive means, the coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air; and means for arresting the plunger relatively to the drive means during the withdrawal stroke of the plunger from the die, to reset its position relatively to the drive means.

9. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a pneumatic coupling between said plunger and said drive means, the coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air; and means for arresting the plunger relatively to the die during the stroke portion by which the plunger is inserted into the die.

10. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die;

reciprocating drive means; a resilient force coupling between said plunger and said drive means, said coupling being adapted to oppose movement of the plunger relatively to the drive means by resilient force; and pressure fluid damping means for damping the action of said coupling.

11. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a first resilient force coupling between said plunger and said drive means, said first coupling being adapted to oppose movement of the plunger relatively to the drive means in one direction by resilient force; a second resilient force coupling between said plunger and said drive means, said second coupling being adapted to oppose movement of the plunger relatively to the drive means in the opposite direction by resilient force; and pressure fluid damping means for damping the action of said first and said second coupling.

12. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a first resilient force coupling between said plunger and said drive means, said first coupling being adapted to oppose movement of the plunger relatively to the drive means in one direction by resilient force; a second resilient force coupling between said plunger and said drive means, said second coupling being adapted to oppose movement of the plunger relatively to the drive means in the opposite direction by resilient force; first pressure fluid damping means for damping a the action of said first coupling; and a second pressure fluid damping means for damping the action of said second coupling.

13. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a first pneumatic coupling between said plunger and said drive means, said first coupling comprising a first cylinder and a first piston movable in said cylinder; a second coupling parallel to said first coupling, said second coupling comprising a second cylinder and a second piston movable in said second cylinder; first air passage means providing a passage for air between the first cylinder and the surrounding atmospheric air; first air passage restricting means for restricting the flow of air between said first cylinder and the surrounding atmospheric air during movement of the plunger relatively to the drive means in one direction; second air passage means providing a passage for air between said second cylinder and the surrounding atmospheric air; and second air passage restricting means for restricting the flow of air between said second cylinder and the surrounding atmospheric air during movement of the plunger relatively to the drive means in the opposite direction.

14. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a first pneumatic coupling between said plunger and said drive means, said first coupling comprising a first cylinder and a first piston movable in said cylinder; a second coupling parallel to said first coupling, said second coupling comprising a second cylinder and a second piston movable in said second cylinder; first air passage means providing a passage for air between the first cylinder and the surrounding atmospheric air; first air passage restricting means for restricting the flow of air through said first air passage means; a first check valve parallel to said first air passage restricting means, said first check valve being oriented to close to passage of air through it during movement of the first piston relatively to the first plunger in one direction; second air passage means providing a passage for air between said second cylinder and the surrounding atmospheric air; second air passage restricting means for re stricting the flow of air between said second cylinder and the surrounding atmospheric air; and a second check valve parallel to said second air passage restricting means, said second check valve being oriented to close to passage of air through it during movement of the second piston relatively to the second cylinder in the opposite direction.

15. A box forming machine comprising, in combination, a frame; a die mounted on said frame; a plunger movable into and out of said die; a drive element mounted on said frame with freedom of reciprocating motion in a direction substantially parallel to the die axis; a first and a second cylinder mounted on said drive element; a plunger head supporting said plunger; a first piston and a second piston connected to said plunger head, said first piston being movable in said first cylinder, said second piston being movable in said second cylinder, said first and said second pistons forming a first and a second cylinder chamber with the'rc'spective cylinders; air passage means between said first chamber and the surrounding atmospheric air; a first air flow restricting means for restricting the flow of air through said first air passage; a second air flow restricting means for restricting the flow of air through said second air passage; a first check valve opening to air flowing from, and closing to air flowing into, said first chamber and a second check valve closing to air flowing from, and opening to air flowing into, said second chamber.

16. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air; and stroke limiting means between said drive means and said plunger for positively moving said plunger during the re moval stroke out of said die.

17. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die;

reciprocating drive means; a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air; and stroke limiting means between said plunger and said die for arresting said plunger during the insertion stroke into said die prior to the reversal point of said drive means.

18. A box forming machine comprising, in combination, a die; a plunger movable into and out of said die; reciprocating drive means; a pneumatic coupling between said plunger and said drive means, said coupling comprising a cylinder, a piston movable in said cylinder and subdividing said cylinder into two chambers, and means for establishing a restricted air path between at least one of said chambers and the surrounding atmospheric air, the freedom of motion of the piston relatively to the cylinder in relation to the reciprocating motion of the drive means being sufiicient to cause the plunger to move fully into the die in one extreme position of the piston relatively to the cylinder while the drive means is at its reversal point nearest the die, and to cause the plunger not'to enter the die in the other extreme position of the piston relatively to the cylinder for the same reversal point of the drive means; and means responsive to the position of the plunger relatively to the die at said reversal point for stopping said drive means.

References Cited in the file of this patent UNITED STATES PATENTS 

